Reusable PCR amplification system and method

Abstract

A DNA amplification device utilizing a polydimethylsiloxane (PDMS) and silicon substrate coated with spin-on glass (SOG) is provided. This PDMS layer is irreversibly bonded to the SOG layer of the silicon substrate using oxygen plasma. The amplification device is an inexpensive, microfluidic device, which can be utilized as a portable thermo-cycler to perform PCR amplification of DNA in the field.

1. A device for use in micro fluidic applications, the device comprising a substrate a portion of the substrate being coated with a layer of spin-on glass; a polydimethylsiloxane layer bonded to the spin-on glass layer, wherein the spin-on glass layer and the polydimethylsiloxane layer are exposed to oxygen plasma prior to bonding. 
     
     
       2. The device of  claim 1 , wherein the substrate is a silicon substrate surrounded by an insulating layer. 
     
     
       3. The device of  claim 2 , further comprising: one or more heaters deposited on the insulating layer of the lower surface of the substrate. 
     
     
       4. The device of  claim 2 , wherein the insulating layer is an oxide layer. 
     
     
       5. The device of  claim 1 , wherein the polydimethylsiloxane layer defines at least one fluid path including a fluid inlet, a chamber, and a fluid outlet. 
     
     
       6. The device of  claim 5 , further comprising: at least one wash reservoir for holding a washing liquid; at least one waste reservoir for receiving the washing liquid; and one or more peristaltic pumps for providing a fluid connection between the wash reservoir, the at least one fluid path, and the waste reservoir. 
     
     
       7. The device of  claim 1 , wherein the spin-on glass layer is exposed to the oxygen plasma under conditions that produce a contact angle of 5° or less for the spin-on glass. 
     
     
       8. The device of  claim 1 , wherein the polydimethylsiloxane layer is exposed to the oxygen plasma under conditions that produce a contact angle of 5° or less for the polydimethylsiloxane. 
     
     
       9. The device of  claim 3 , wherein the heaters are serpentine heaters based on a design determined by solving a two-dimensional steady state heat conduction problem with boundary conditions determined by the temperature requirements for a desired PCR process. 
     
     
       10. The device of  claim 1 , wherein the spin-on glass comprises methyl silsequioxane. 
     
     
       11. The device of  claim 4 , wherein the spin-on glass layer is deposited on the oxide layer.